If u use gcin in Linux, the system shows the char '「' as u enter `Ctrl + [`. It's a trouble if u're a VIM user. To solve it, u can follow the steps.
1. `cp /usr/share/gcin/table/phrase-ctrl.table ~/.gcin`
2. `vim ~/.gcin/phrase-ctrl.table`
3. comment it, `# [ 「`
4. restart it